Supervised instruction with stuff like that isn’t a bad thing. Letting your 8yr old have a bagful of leftover fourth of July goods will probably not turn out OK.
It’s not a certain thing but ups the odds. Kind of like wearing seat belts. Or motorcycle helmets. You play actuary with your health and safety.
My friend had a lot of ongoing health issues related to his injury while we were growing up. And he has been prevented from doing a good many things because of it as well. His brother joined the military. He wasn’t able to. etc.
Given my druthers I wouldn’t let kids play with something that might, in fact, kill them until they are old enough to comprehend ‘danger’ and ‘safety’ and ‘common sense’. My friend danged near burned his house down that day as well. The fort was under the carport.
I left out the part where he burned down his neighbor’s bushes playing with firecrackers. It was not done maliciously. I don’t know where he would be today if he had done the same in this era.